With the increased prevalence of electronic imaging devices and the Internet, billions of images have become publically available and searchable online. However, many images do not include an accurate description or tagging, increasing the difficulty of identifying such images using typical keyword techniques. Consequently, when a user desires to locate an image having particular features, conventional text-based search engines that rely on short text queries are often unable to locate desired images in a timely and efficient manner. Thus, in some cases, a hand-drawn sketch may be used as at least part of a search query for locating a desired image. However, machine identification of the subject of hand-drawn sketches can be difficult. Additionally, while image-based searching of image collections has been intensively studied, little progress has been made in developing practical large-scale sketch-based recognition techniques.